Sensors could monitor water quality around the world in real-time

Currently, if the water quality of a lake, river, or body of wastewater needs to be tested, a sample is collected and taken back to a lab to test for things like nitrate levels, heavy metals or other pollutants. This process not only takes a lot of time, but is also very expensive when you're monitoring several bodies of water continuously. Researchers at University of Western Australia see a future where water quality data is instantly available and inexpensive, thanks to a new type of environmental sensor they've developed.

The team, led by Professor Giacinta Parish, is calling their new technology a new kind of sensor. It's made from gallium nitride, a material that can perform in extreme heat and at high power levels, unlike the materials silicon and gallium arsenide that are often used in sensor chips.

Parish's team along with engineers from CSIRO have used the gallium nitride to build a single sensor chip that can detect many different ions without the need for a reference electrode that would add to its size and weight. The team has developed an array of chemical sensors based on this technology that could be placed in any body of water to deliver real-time, continuous monitoring of water quality.

"If you can have sensors through the entire water system, rather than sampling at specific points and then having to remove those samples and test them in the laboratory, this enables a more a effective real time monitoring of critical water quality characteristics such as heavy metal ion content, nitrate content, or pH," Parish says.

The sensors could monitor nitrate levels in ponds and lakes to get ahead of algae blooms that occur when nitrates are raised. Heavy metals and other pollutants could be monitored in wastewater and oceans could be monitored for acidification due to climate change.

These sensors could help agencies like the EPA, Water Corporation, Department of Water and others to both monitor water quality around the world and take important steps based on the data they provide to protect bodies of water from pollution.